Microsoft Security Essentials, the newly released free antivirus by Microsoft, has a clean and modern interface, with few options to confuse users. The detection rates are very good, in particular the detection of zero-day threats and rootkits. Even more impressive, Security Essentials has very few false positives and is light on resources.

Microsoft Security Essentials is by far the best choice for average users because of the minimal user interaction required. It automatically updates and removes threats. No registration is needed, apart from a quick validating of Windows, and there are no nag screens or advertisements.

The main downsides are the slow scan speeds and the lengthy amount of time it takes to quarantine malware. Note that Microsoft Security Essentials requires a genuine copy of Windows to install.

Microsoft Security Essentials